Leveling platform for sheet material



March 8, 1966 H. D. REEVES LEVELING PLATFORM FOR SHEET MATERIAL 2 Sheets-Sheet 1 Filed NOV. 15, 1963 Hudson 0. Hwves INVENTOR.

March 8, 1966 H. D. REEVES 3,239,219

LEVELING PLATFORM FOR SHEET MATERIAL Filed Nov. 13, 1963 2 Sheets-Sheet 2 Hudson 0. Reeves INVENTOR.

United States Patent Ofiice 3,239,219 Patented Mar. 8, 1966 3,239,219 LEVJELING PLATFORM FOR SHEET MATERIAL Hudson 1). Reeves, Garrard, Calif. (127 Vernon Way, Santa Paula, Calif.) Filed Nov. 13, 1963, Ser. No. 323,403 Claims. (Cl. 271-61) This invention comprises a novel and useful stack leveling platform for sheet materials and more particularly pertains to a leveling device whereby a stack of pliable sheet material such as paper may have its corners at its base vertically adjusted or leveled to facilitate subsequent operations such as the feeding of individual top sheets from the stack by the feeding mechanism of an automatic printing press and the like.

The invention set forth herein is a modification of the invention disclosed and claimed in my copending application, Serial No. 323,283, filed November 13, 1963, for Wedge Type Stack Leveling Platform for Sheet Material.

It is frequently desirable in many industries as for example in the operation of automatic printing presses and for various operations as for example the feeding of sheets of material from a stack of sheets to provide means for adjustably leveling the corners at the bottom of the stack of sheets in order to insure positioning of the stack top sheets in a horizontal plane. Owing to their pliability, it frequently occurs that the corners of the base of a stack of sheets may be out of level with each other. This condition in turn can result in the topmost sheets being out of conformity with a horizontal plane thereby rendering more diflicult and uncertain the automatic feeding of the sheets from the stack by various machines and for various purposes.

It is therefore the primary purpose of this invention to provide a device which will facilitate the leveling of the corners of the base of a stack of sheets and to enable individual adjustments of the elevation of each corner as may be required to bring the stack into a desired level condition.

It is therefore an important object of this invention to provide a leveling device which may be easily and removably applied to the underside of a stack of sheets and which will enable an accurate leveling of the base of the stack of sheets.

A further object of the invention is to provide a leveling unit in accordance with the foregoing object which will enable the opposite corners at one side of a stack of sheets to be accurately adjusted and leveled.

A further object of the invention is to provide a device including a plurality of leveling units each of which shall have an adjustable leveling element extensible above the top support surface of the unit to effect a jacking action and leveling action upon the base of a stack of sheets supported thereon.

An additional purpose of the invention is to provide a leveling unit having a pair of spaced leveling elements movably mounted thereon and whereby the elements may be individually adjusted and whereby such adjustment may be effected from one end only of the unit.

A further important object of the invention is to provide a leveling unit in accordance with the foregoing objects which will support and level one side of a stack of sheets and will individually level the proximate and remote corners at that side of the stack of sheets.

Still another important purpose of the invention is to provide a leveling unit in compliance with the preceding objects wherein the entire operating mechanism of the leveling device shall be compactly and completely enclosed and housed within the body of the unit.

Still another important purpose of the invention is to provide a leveling unit in accordance with the preceding objects wherein portions of the top wall of the housing of a leveling unit shall be upwardly tiltable as the corner leveling elements or plates of the unit.

And a final important object of the invention to be specifically enumerated herein resides in the provision of a leveling device in accordance with the foregoing objects whereby a screw and wedge mechanism may be utilized to adjustably raise particular portions of the surface of the leveling device to thereby individually adjust corners of a stack of sheets for leveling purposes, and whereby the spacing between the individual leveling elements of a unit may be adjustably varied from time-totime as may be necessary to accommodate the device to a stack of sheets of a particular size.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a fragmentary perspective view showing a portion of a stack of sheet material with the corner leveling device of this invention applied thereto, the stack of sheets being shown in association with a portion of a conventional type of printing press to which the sheets are individually fed during the printing operation;

FIGURE 2 is a perspective view of one of the leveling units of the device with the corner leveling plates being disposed in a corner-leveling position;

FIGURE 3 is a perspective view similar to FIGURE 2 but showing the position of the corner leveling elements when they are retracted or flush with the surface of the unit in their non-adjusted positions;

FIGURE 4 is a fragmentary view in vertical longitudinal section taken substantially upon the plane indicated by the section line d4 of FIGURE 3, parts being broken away, and showing the actuating mechanisms together with their association with the leveling elements with the latter being in their retracted positions;

FIGURE 5 is a fragmentary view in vertical longitudinal section taken substantially upon the plane indicated by the section line 55 of FIGURE 2 and showing the actuating mechanism and a leveling element in a leveling element adjustably extended position;

FIGURE 6 is a view in vertical transverse section taken upon an enlarged scale substantially upon the plane indicated by the section line 6-6 of FIGURE 2 with parts being broken away;

FIGURE 7 is a vertical transverse sectional view taken upon an enlarged scale substantially upon the plane indicated by the section line 77 of FIGURE 2 with parts being broken away; and,

FIGURE 8 is a perspective view of one of the toggle link connecting means forming a part of the actuating mechanism for the corner leveling unit of the invention.

Referring now first to FIGURE 1 it will be observed that the numeral 10 designates a portion of a conventional type of printing press having a stack-supporting platform 12 at one side thereof upon which is supported a stack of sheets of paper as at 14, which in operation of the press are to be individually supplied to the printing mechanism of the press. In accordance with this invention there are mounted upon the platform 12 a pair of leveling units each indicated by the numeral 20 and upon whose top surfaces the stack of sheets 14 is supported. Any desired number of filler blocks 22 may be rested upon the platform 12 and between the leveling units 20 to fill up the space therebetween and provide adequate support for the base or underside of the stack of sheets.

Inasmuch as the leveling units 20 are of identical construction, and since the essence of this invention resides in the actual structure and operation of a leveling unit 20, attention will now be directed specifically to the remaining figures of the drawings for an explanation of the structure and of the operation of such a unit.

The leveling unit 20 is of a horizontally elongated hollow box-like construction consisting of a hollow body having what may be termed front and rear end walls of which the former is shown at 22 and the latter at 24, together with a pair of side walls each indicated by the numeral 26 and accompanied by a bottom wall 28 and a top wall 30. The top wall 30 comprises a horizontal supporting surface upon which the bottom side or face of the stack of sheets 14 is to be supported.

The top wall 30 is provided with a pair of openings 32 and 34 therein at the front and rear ends of the body in which are received corner-leveling elements indicated generally by the numerals 36 and 38 respectively.

Referring especially to FIGURES 2 and 4, it will be seen that the rear corner leveling element 38 is in the form of a leveling plate 40 having a bifurcated end which is pivotally secured as by a pivot pin 42 to the side walls 26 so that as will be seen from a comparison of FIG- URES 2, 3 and 4, the rear corner leveling element 38 may be selectively pivoted from a retracted position wherein it is disposed within the opening 34 flush with the top wall 30 to an elevated, extended or raised position as shown in FIGURE 2 where it projects above the horizontal surface of the top wall 30 and thus will effectively raise or jack upwardly the corner of the stack of sheets 14 disposed thereabove.

The forward or front leveling element 36 which is mounted in the opening 32 at the front end of the unit is longitudinally adjustable in that opening whereby its distance from the rear leveling element 38 may be adjustably varied in order that the two leveling elements may accommodate themselves to stacks of sheets having different widths between the corners thereof.

Referring now specifically to FIGURES 2, 4-7, it will be seen that the forward leveling element 36 consists of a fiat base plate 50 to which is hingedly connected a lifting plate 52 by means of a hinge or pivot pin 54. Referring especially to FIGURE 7 it will be seen that the inner surfaces of the two body side walls 26 are provided with inwardly projecting longitudinally and horizontally extending flanges or rails 56 upon the top sides of which are slidably supported the base plate 50 and the lift plate 52 when the latter is in its lowered position as seen in FIGURES 3 and 4. The base plate is provided with a transversely extending retaining plate 58 secured to its underside as by a fastener 60 which retaining plate is provided with a shouldered recess 62 for embracing the ad jacent flange or rib 56 whereby this rib is clamped between the base plate 50 and the retaining plate 58 for sliding movement of the forward leveling element 36 upon the ribs 56. Thus, it will be seen that the forward element 36 is retained in the forward opening 32 for longitudinally adjustable sliding movement therein with the base plate 50 being flush with the top surface 30 and with the lift plate 52 being adjustable between a flush retracted position shown in FIGURES 3 and 4 and an elevated, extendeil or raised position shown in FIGURES 2 and 5.

Actuating means are provided for independently adjusting the operation or upward tilting and lifting action of the lifting elements 36 and 38. The actuating means are of substantially identical construction, each consisting of an actuating rod 60 and 62 for the front and rear lift elements 36 and 38 respectively, each rod being received through an opening 64 in the front end wall 22 and being rotatably retained therein against axial displacement as by a pair of collars 66 and 68 removably secured to the rod. The extending ends of the rod are provided with transversely disposed pins as at 70 whereby a handcrank as at 72 may be removably placed upon either rod for effecting adjustment thereof.

It will be observed that each rod is secured and supported solely at its portion extending through the opening 64 except for the operation of a connecting means by which the rod is operatively connected to the associated lifting element 36 or 38. The connecting means as shown particularly in FIGURE 8 consists of a scissors or toggle linkage assembly comprising a set of four links 74, 76, pivoted to each other as at 78 and 80, 82 pivotally connected at 84. The upper links 74 and 76 are pivotally connected as by pivots 86 and 88 to the lower links and 82, with these last-mentioned pivots carrying thereon internally bored sleeves 90 and 92 which are engaged upon the actuating rods 60 or 62. One of these sleeves is threadedly engaged upon a threaded portion as at 94 of one of the rods while the other sleeve is freely slidable thereon. An adjustable collar 96 on the rod provides an adjustable abutment for the slidable sleeve, which as shown in FIGURES 4 and 5 is the sleeve 90, with the other sleeve 92 being threadedly engaged upon the rod for axial movement along the rod by rotation of the rod.

Secured to the upper and lower pivots 78 and 84 are upper and lower abutment or pressure blocks 98 and 100 adapted to respectively be secured to the underside of the lift plates 52 or 38 and to slidably bear against the bottom wall 28 of the housing or body. Thus, rotation of the actuating rods serves merely to vary the spacing between the two sleeves 90 and 92 and thus to vertically extend or contract the pivots 78 and 84 and thus the pressure or abutment blocks 98 and 100. In this manner, the actual thrust of the lifting operation is borne by the scissor linkage of the connecting means by which the weight on the lifting plate 52 or 38 is directly applied to the bottom wall of the unit thereby relieving the actuating rod from this strain.

In order to effect adjustment of the plates with respect to each other, it is evident that the abutment collar 96 may be adjusted along the rod 60 or 62 with the threaded sleeve 92 being likewise longitudinally adjusted upon its associated rod.

Although the leveling device has been described as especially adapted to the adjustable lifting of the corners of a stack of sheet material, it is equally applicable to adjustably elevating other portions of the stack, particularly in the case of a stack having sheets of relatively large area wherein adjustable leveling of portions between corners is beneficial.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A stack leveling unit for a stack of sheet material comprising a hollow, horizontally elongated body for use as a support, said body having a top wall constituting a support surface with longitudinally spaced openings therein, a leveling element in each opening movably mounted upon said body for vertical movement between a retracted position within its opening and an extended position projecting above said top wall, actuating means, one connected to each element disposed in said hollow body, each element being pivotally mounted upon said body, and means for adjusting the spacing between said elements whereby each element may be adjusted to engage and lift a corner of a stack of sheets.

2. The combination of claim 1 wherein said adjusting means includes a longitudinally extending guideway in said body at one of said openings and the associated element is slidingly and guidingly mounted upon said guideway.

3. The combination of claim 2 wherein said last-mentioned element comprises a base plate mounted in said guideway and a vertically tiltable lift plate pivoted to said base plate, means connecting said actuating means to said lift plate.

4. The combination of claim 3 wherein said actuating means comprises a rod axially fixed but rotatably mounted in said hollow body solely at one end of each, said connecting means being screw-threadedly engaged with said rod.

5. The combination 'of claim 4 wherein said connecting means comprises a scissors linkage having opposite axial ends engaged upon said rod and having upper and lower thrust members respectively engaging said lift plate and said body whereby upon pivoting action of said scissors linkage the lifting thrust upon said lift plate will be applied directly to said body.

References Cited by the Examiner UNITED STATES PATENTS 1,407,719 2/1922 Boner 254-104 1,800,384 4/1931 Haack 254104 X 3,022,997 2/ 1962 Pendley 27161 X M. HENSON WOOD, ]R., Primary Examiner.

W. F. MCCARTHY, Assistant Examiner. 

1. A STACK LEVELING UNIT FOR A STACK OF SHEET MATERIAL COMPRISING A HOLLOW, HORIZONTALLY ELONGATED BODY FOR USE AS A SUPPORT, SAID BODY HAVING A TOP WALL CONSTITUTING A SUPPORT SURFACE WITH LONGITUDINALLY SPACED OPENINGS THEREIN, A LEVELING ELEMENT IN EACH OPENING MOVABLY MOUNTED UPON SAID BODY VERTICAL MOVEMENT BETWEEN A RETRACTED POSITION WITHIN ITS OPENING AND EXTENDED POSITION PROJECTING ABOVE SAID TOP WALL, ACTUATING MEANS, ONE CONNECTED TO EACH ELEMENT DISPOSED IN SAID HOLLOW BODY, EACH ELEMENT BEING PIVOTALLY MOUNTED UPON SAID BODY, AND MEANS FOR ADJUSTING THE SPACING BETWEEN SAID ELEMENTS WHEREBY EACH ELEMENT MAY BE ADJUSTED TO ENGAGE AND LIFT A CORNER OF A STACK OF SHEETS. 